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Substrate (chemistry)

About: Substrate (chemistry) is a research topic. Over the lifetime, 35902 publications have been published within this topic receiving 740722 citations. The topic is also known as: enzyme substrate.


Papers
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Journal ArticleDOI
TL;DR: Dopa is the most effective hydrogen donor and will eliminate the lag period when used in catalytic amounts and 3,4-Dihydroxyphenylalanine at high concentration is an inhibitor of tyrosine hydroxylation, while tyrosinase acts as a substrate inhibitor at concentrations above 8 x 10-4 m.

350 citations

Journal ArticleDOI
TL;DR: A detailed analysis of the binding of N-formyl-l-tryptophan to the active site of α-chymotrypsin shows that the indolyl side chain lies in a hydrophobic pocket or slit, which accounts for the specificity of this enzyme for binding arginine or lysine side chains.

350 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that poly(ethylene glycol) and poly(propylene glycol)-based surfactants are able to increase cellulose conversion with up to 70% in wheat straw.

348 citations

Journal ArticleDOI
TL;DR: The effects of biochar on enzyme activities in soils are highly variable; these effects are likely associated with reactions between biochar and the target substrate and fluorometric assays are more robust to, or account for, this sorption better than the colorimetric assays used herein.
Abstract: We studied the effects of a biochar made from fast pyrolysis of switchgrass on four soil enzymes (β-glucosidase, β-N-acetylglucosaminidase, lipase, and leucine aminopeptidase) to determine if biochar would consistently modify soil biological activities. Thus, we conducted a series of enzyme assays on biochar-amended soils. Inconsistent results from enzyme assays of char-amended soils suggested that biochar had variable effects on soil enzyme activities, thus we conducted a second experiment to determine if biochar reacts predictably with either enzyme or substrate in in vitro reactions. Both colorimetric and fluorescent assays were used for β-glucosidase and β-N-acetylglucosaminidase. Seven days after biochar was added to microcosms of 3 different soils, fluorescence-based assays revealed some increased enzyme activities (up to 7-fold for one measure of β-glucosidase in a shrub-steppe soil) and some decreased activities (one-fifth of the unamended control for lipase measured in the same shrub-steppe soil), compared to non-amended soil. In an effort understand the varied effects, purified enzymes or substrates were briefly exposed to biochar and then assayed. In contrast to the soil assays, except for β-N-acetylglucosaminidase, the exposure of substrate to biochar reduced the apparent activity of the enzymes, suggesting that sorption reactions between substrate and biochar impeded enzyme function. Our findings indicate that fluorometric assays are more robust to, or account for, this sorption better than the colorimetric assays used herein. The activity of purified β-N-acetylglucosaminidase increased 50–75% following biochar exposure, suggesting a chemical enhancement of enzyme function. In some cases, biochar stimulates soil enzyme activities, to a much greater degree than soil assays would indicate, given that substrate reactivity can be impeded by biochar exposure. We conclude that the effects of biochar on enzyme activities in soils are highly variable; these effects are likely associated with reactions between biochar and the target substrate.

346 citations

Patent
08 May 1991
TL;DR: A cellulose- or hemicellulose-degrading enzyme which is derivable from a fungus other than Trichoderma or Phanerochaete, and which comprises a carbohydrate binding domain homologous to a terminal A region of T. reesei cellulases, is described in this article.
Abstract: A cellulose- or hemicellulose-degrading enzyme which is derivable from a fungus other than Trichoderma or Phanerochaete, and which comprises a carbohydrate binding domain homologous to a terminal A region of Trichoderma reesei cellulases, which carbohydrate binding domain comprises amino acid sequence (α) or a subsequence thereof capable of effecting binding of the enzyme to an insoluble cellulosic or hemicellulosic substrate.

345 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202214
2021807
20201,053
20191,064
20181,112
20171,024